Primitive asteroids belonging to the C-complex groups are considered to be among the most ancient and least thermally altered bodies in the Solar System. They are thought to preserve a record of early Solar System conditions, including the primordial distribution of volatiles and organic compounds that may have played a role in the emergence of life on Earth. Understanding their composition, alteration history, and surface evolution is essential for reconstructing early planetary processes.One of the most widely used techniques for investigating these bodies is low-resolution reflectance spectroscopy, which covers a broad spectral range: from ultraviolet (UV) to near-infrared (NIR) wavelengths. This method allows for the identification of broad absorption features and spectral slopes indicative of surface mineralogy and alteration processes.However, due to the limited quantum efficiency of CCDs in the near-UV (NUV) and atmospheric scattering, most spectroscopic surveys - such as the Small Main Belt Asteroid Spectroscopic Survey (SMASS) I and II [1, 6], and the Small Solar System Objects Spectroscopic Survey (S3OS2) [4]- are constrained to wavelengths above 0.45 μm, leaving NUV absorption largely unexplored. In this work, we aim to explore the presence of hydrated minerals based on spectral key features of primitive asteroids in the NUV-visible range. We investigate properties in the spectra of C-complex asteroids, such as the NUV absorption feature and the 0.7 µm band, to refine our understanding of asteroid surface composition, space weathering effects [3], and aqueous alteration processes [2]. These features serve as crucial indicators of the presence of phyllosilicates and other hydrated minerals.Since November 2023, we have been conducting observations using the 10-meter Southern African Large Telescope (SALT), located in Sutherland, South Africa. SALT is equipped with the Robert Stobie Spectrograph (RSS), which we used to obtain asteroid spectra at a resolution of R = 800. A distinctive advantage of SALT is its enhanced throughput at short wavelengths, reaching down to 0.32 μm in the near-ultraviolet, thanks to the NaCl correction lens.For some observations, we also used the 10.4-meter Gran Telescopio Canarias (GTC), located in La Palma, Spain. It allowed us to observe asteroids that were not accessible from SALT. By observing selected targets with both telescopes, we were also able to check our spectra for instrumental biases.At the conference, we will present the results from our first observing pool, which includes spectra of 25 asteroids and their analysis; outline our ongoing long-term observational program and future plans. We will also discuss our observational strategy, particularly the identification and use of solar analogue stars in the NUV range in the Southern Hemisphere for accurate spectral calibration.Figure 1: Examples of reflectance spectra of several C-type asteroids observed: a-b) with SALT in the range 0.32-0.9 μm; c-d) with GTC in the range 0.35-1.0 μm. Asteroid spectra have been divided by spectra of the solar analogue star SA112-1333, obtained on the same night as the asteroids. All spectra have been normalized to 1 at a wavelength of 0.55 μm..Acknowledgments: Part of observations reported in this abstract were obtained with the Southern African Large Telescope (SALT). This work has been done under the SALT programs 2023-2-SCI-025, 2024-1-SCI-012 and 2024-2-SCI-005 (PI: T. Kwiatkowski). Polish participation in SALT is funded by grant No. MEiN nr 2021/WK/01. This work has been done under the GTC program GTC37-24A (PI: J. de León). JdL acknowledges support from the Agencia Estatal de Investigación del Ministerio de Ciencia e Innovación (AEI-MCINN) under grant "Hydrated Minerals and Organic Compounds in Primitive Asteroids" with reference PID2020-120464GB-100.References: [1] Bus, Binzel (2002) Icarus, 158, 1; [2] Fornasier et al. (2014) Icarus, 223; [3] Hendrix & Vilas (2019) Geophys. Res. Lett., 46, 24; [4] Lazzaro et al. (2004) Icarus, 172, 1; [5] Vilas (1994) Icarus, 111, 2; [6] Xu et al. (1995) Icarus, 115, 1